LANSING -- The Archives of Michigan has received an extensive collection, one of the largest in the country, of Civil War letters, it announced Tuesday.

The 291 letters donated by Wallace K. Ewing, of Grand Haven, will be available to researchers visiting the archives, and electronic versions will be added in the spring to the Archives of Michigan Digital Collection at www.seekingmichigan.org.

The collection consists of correspondence between Ewing's great-grandparents -- Henry McKendree (Mack) and Nancy (Nan) Ewing of Hillsdale -- from 1856 to 1865, while Mack was fighting in the Civil War. All of the letters are in their original addressed, stamped and canceled envelopes.

The donation also includes a notebook kept by Mack and a scrapbook made by Nancy Ewing during the war.

"We're thrilled to be able to make this amazing collection, which offers a fascinating look at Michigan's and the nation's history, available to researchers," said State Archivist Mark Harvey in a news release.

Ewing is a former English professor who now works at the Tri-Cities Historical Museum of Grand Haven. He published a selection of 85 of the letters, titled "From Home to Trench: The Civil War Letters of Mack and Nan Ewing," in 2000. He also has authored several books about Grand Haven-area history.